Smoke rises after shelling in the town of Novoazovsk, eastern Ukraine, on Aug. 26. / Sergei Grits, AP

by Doug Stanglin, USA TODAY

by Doug Stanglin, USA TODAY

Heavily armed Russian-backed forces pushed west in an offensive along Ukraine's southern coast Wednesday, taking new territory far from previous fronts in the conflict.

The offensive creates a new southeastern front and raised the prospect that separatists seek to create a land link between Russia and the Crimea.

After a third day of heavy shelling that sent many residents fleeing, rebel fighters with dozens of tanks and armored vehicles entered Novoazovsk, a resort town of 40,000 on the Azov Sea, the mayor told the Associated Press.

Polish Prime Minister Donald Tusk said the North Atlantic Treaty Organization has evidence that Russian army units are now operating directly in eastern Ukraine, the Wall Street Journal reported.

"Nobody can seriously accept talk of 'separatists' in Ukraine anymore," Tusk told the Polish parliament. "The information is from NATO and confirmed by our intelligence, and is basically unambiguous."

The move comes despite Ukrainian President Petro Poroshenko's efforts to push a peace plan in his two-hour meeting Tuesday with Russian President Vladimir Putin.

Rebel forces lobbed at least 10 shells at Novoazovsk. Plumes of black smoke rose above the town, which was also hit repeatedly by shelling Tuesday, injuring four people, Mayor Oleg Sidorkin said, according to an Associated Press reporter in the town.

In Washington, the State Department accused Russia of orchestrating a new military campaign in Ukraine that is helping rebel forces expand their fight and sending in tanks, rocket launchers and armored vehicles.

"These incursions indicate a Russian-directed counteroffensive is likely underway in Donetsk and Luhansk," State Department spokeswoman Jen Psaki told reporters. She also voiced concern about overnight deliveries of materiel in southeast Ukraine near Novoazovsk, and said Russia was being dishonest about its actions, even to its own people.

The fighting comes only days after Ukraine said a convoy of Russian military equipment crossed the border into southeastern Ukraine, which had been largely untouched in months of fighting in eastern Ukraine between the Ukrainian troops and separatists.

Novoazovsk lies on a coastline road that runs from Russia to the major Ukrainian port of Mariupol and west to Crimea, raising fears the separatists are seeking to create a land link between Russia and Crimea, which Russia annexed in March.

The attack also appeared to be part of a counteroffensive against Ukrainian forces that have made strong gains against the rebels in recent weeks, including surrounding the separatist strongholds of Donetsk and Luhansk. Separatists have declared those two areas as independent republics and sought to have them annexed by Russia.

At least 2,119 people had been killed and 5,043 wounded in fighting since mid-April, according to the latest report from the United Nations.

Ukrainian troops on Wednesday were also trying to hold the town of Ilovaysk, east of Donetsk, and two other towns, the Ukrainian military press service said on Facebook.

The continued fighting reflects the inconclusive talks between the Ukrainian and Russian leaders Tuesday on the sidelines of a regional economic summit in the Belarusian capital, Minsk.

Poroshenko called the talks "overall positive" and said Putin had accepted the principles of his peace plan, which includes an amnesty for those in the east not accused of serious crimes and calls for some decentralization of power to the region.

Putin challenged that assertion, however, saying the conflict was "Ukraine's business" and that only Kiev could work out a cease-fire with rebels.

Russia "can only help to create an atmosphere of trust for this important and necessary process," Putin said. "We in Russia cannot talk about any conditions for the cease-fire, about any agreements between Kiev, Donetsk, Luhansk," the two rebel regions.

Moscow has repeatedly denied charges by Kiev and the West that the Kremlin is supplying arms and expertise to the rebels in eastern Ukraine. Putin, and the Russian Defense Ministry, suggested that 10 Russian paratroopers captured inside Ukraine on Monday had been on patrol and accidentally crossed an unmarked border.

Meanwhile, AP journalists on the border have reported seeing rebels with a wide range of unmarked military equipment - including tanks, Buk missile launchers and armored personnel carriers - and have run into many Russians among the rebel fighters.

The Kiev government reported spotting two convoys of Russian military vehicles entering Ukraine from Russia in recent days, including one on the road to Novoazovsk on Monday.

In Kiev, Andriy Lysenko, a spokesman for the Ukrainian National Defense Council, told reporters Wednesday that the latest convoy from Russia with five armored infantry carriers and a Kamaz truck carrying men entered the town of Amvrosiyivka.

"If this tactical group got lost and accidentally came into Ukraine like the paratroops of the 98th paratroop division then it remains for us to remind them that they can return to Russia, taking an easterly direction," Lysenko remarked.

It noted the recent capture of the Russian soldiers on Ukrainian territory and reports of "mysterious funerals" of Russian soldiers, some of whom are officially counted dying during training exercises.

"The number of questions that hang in the air of the dead and detained Russian troops on the territory of Ukraine has reached a critical number. Does Russia fight in Ukraine and, if so, on what grounds? If not, then who is in those freshly dug graves or giving testimony at SBU (Russian Security service) interrogations?""

Pointing to secret involvement in the past of Russian soldiers in Afghanistan and Chechnya, the editorial said that "(i)n either case, war and attempts to conceal information about casualties among its soldiers contributed to the development of the crisis in society and the fall political support of the authorities."